Immunologic reactivity towards ocular antigens has been demonstrated in patients with uveitis. However, the specificity and importance of anti-ocular antibodies, cellular reactivity toward ocular antigens, or circulating immune complexes is unclear. This proposal will investigate the nature and importance of ocular antigens in the immunopathology of human and animal uveitis. Antibodies specific for ocular antigens which are present in patients' sera may be important in the pathophysiology of uveitis. Uveal and retinal tissues dissected from human eyes, guinea pig eyes and control tissues, will be extracted and partially purified. Serum from patients with retinal vasculitis, iridocyclitis and diffuse uveitis will be tested for specific humoral reactivity against these crude and purified ocular antigens using high resolution analytical procedures. The ocular antigens reactive with patients sera will be obtained in larger quantities (from both human and guinea pig tissues) by preparative immunochemical methods and will be used to develop an experimental allergic uveitis (EAU) model in guinea pigs. The biochemical and immunocytochemical nature of the antigens capable of inducing EAU will be investigated. Attempts will be made to compare these antigens with the antigenic components isolated from immune complexes present in serum from uveitis patients. Results from these investigations will increase our understanding of the immunological mechanisms involved in ocular inflammation. Charaterization of ocular antigens and humoral immune responses against them may increase the clinicians ability to correctly disgnose, treat and predict the course of disease in some forms of uveitis and this is a long range goal of the proposed research.